The quantities and types of organic wastes being generated has grown significantly over the past decade. Many of these organic wastes are hazardous in that they present significant environmental and health hazards. Hazardous wastes previously disposed of by unacceptable methods continue to be discovered in various wastes sites. Improved methods for treatment and disposal of these hazardous wastes are required to meet environmental standards and to treat these wastes in a cost-effective manner.
Recently, there have been increased research efforts aimed at improving the methods used to deactivate hazardous materials at problem waste sites. It is desirable to treat these wastes so that they can be reused, converted into a less hazardous material or be disposed of in a stabilized form to reduce environmental concerns. Technologies currently being developed and employed include wet air oxidation, ozonation, molten salt combustion, electrochemical oxidation, neutralization, catalytic hydrogenation and incineration. Continued development and improvement of cost effective environmentally acceptable treatment technologies for many hazardous wastes are still required.
Several commercial treatment technologies exist for treating low organic content water streams (&lt;1000 ppm) by using conventional water purification methods and for treating high concentration streams (&gt;10%) by various costly methods including solvent extraction and incineration. However, there exists the need to be able to treat concentration ranges not presently commercially treatable (1-5%), as well as other concentration ranges.
Conversion of some waste organic materials, such as contained in biomass materials, to low-BTU fuel gas, carbon monoxide and hydrogen by pyrolysis and substoiciometric burning is well known. Studies undertaken to optimize this process have demonstrated that high temperatures with or without catalysts are required to minimize tar and char formation in this reaction. Recent interest in organic conversion has been aimed at production of a medium-BTU gas through the use of a steam and/or oxygen gasification environment. These processes would produce a cleaner carbon monoxide/hydrogen gas mixture which would be used for synthesis of methane as well as other products.